Navigation devices that provide route information up to the set destination to a driver are being widely used. In existing navigation devices, route information is displayed on a screen of a monitor disposed in the vicinity of a consol or displayed by using a separate device. Here, a user may generally recognize the route information through displayed information and voice information.
Head up displays (HUDs) project information such as a speed of a vehicle and a flow rate or image information such as images of a nightvision and a rear view monitor onto a windshield by using a mirror in a state in which the images are enlarged by a lens to allow the driver to easily recognize the information, thereby securing safety.
However, the head up displays are being only used for displaying a virtual preceding vehicle or displaying a speed or driving direction of the vehicle so as to keep a safety distance with respect to a forward vehicle.